Nonequilibrium phases, formation during

Microsyneresis is a consequence of the polymer-solvent interaction and occurs during the network formation (crosslinking). Microsyneresis is not stable in time it is a nonequilibrium phase that passes in an equilibrium syneresis (macrosinereza). This transition from micro- to macrosyneresis is due to network deformation, which explains the volume change that takes place in the cross-linked structures. 

The dynamics and pattern formation during phase separation processes have been a subject of many experimental and theoretical studies over the past decades as a fascinating example of nonlinear, nonequilibrium phenomena [1,2]. If a binary mixture is rapidly quenched from the single-phase region to the spinodal region of the phase diagram by changing thermodynamic variables, such as temperature and pressure, the mixture becomes thermodynamically unstable and separates, via spinodal decomposition (SD), into two phases. If the volume fraction of one of the phases is close to 0.5 ( isometric case ), the phase-separated structure is implied to be periodic and bicontinuous with the aid of theories [50], experiments [51, 52], and computer simulations [53-56]. 

The formation of the latent image should be considered as a photo-induced transformation of the dielectric molecular silver phase into the metallic one." (230). During chemical sensitization the silver halide grains pass into a nonequilibrium... 

Also appearing in Figures 2 and 3 is a small intermediate peak in the 0°-100°C range, which is similar to one previously reported (33,35) for the homopolymers and postulated to arise from the relaxation of frozen stresses. Its absence in Figure 1 (and in data reported below on all of the one-phase systems) suggests that this intermediate peak appears because of nonequilibrium strain states originating during the formation of microphases. Future studies will feature this observation. 

During the preparation of macroporous materials by crosslinking copolymerization in the presence of precipitants, phase separation takes place within a relatively short period of time. This fast phase separation naturally results in the formation of microdroplets of the rejected porogen. Since the conversion of comonomers at that moment is very low, the rapidly growing polymeric network fixes in the gel the emerging liquid droplets. The nonequilibrium microsyneresis thus transforms into the stable form of phase separation within a heterogeneous system. Thus, the fast arrival at the unstable local polymer-solvent relationship, as compared with the slow rates of solvent macrosyneresis and of network relaxation, leads to the formation of gel-included microdroplets and, finally, to a permanent macroporous structure of copolymers. 

The film formation in fhe spin-coating process for the polymer/fuller-ene blend system in the mixture solvent is a complex process because it is a nonequilibrium state that both thermodynamic and kinetic parameters can influence phase separation, and the system contains four components with dissimilar physical/chemical properties. We found the donor/acceptor components in the active layer can phase separate into an optimum morphology during the spin-coating process with the additive. Supported by AFM, TEM, and X-ray photoelectron spectroscopy (XPS) results, a model as well as a selection rule for the additive solvent, and identified relevant parameters for the additive are proposed. The model is further validated by discovering other two additives to show the ability to improve polymer solar cell performance as well. 

Although much work has been done to study equilibrium behavior in surfactant systems many nonequilibrium dynamic behavior are still far from well understood. When neat or concentrated surfactant is contacted with solvent complicated diffusion process occurs due to the presence of mesophase at the interface. Initially, at the interface, the formation, type and structure of the mesophase will influence the subsequent dynamics. In some cases the interface can become unstable during dissolution and rather striking instabilities form. To obtain a good understanding of such complicated nonlinear processes has relied on a systematic study of the equilibrium phase behavior in such systems. This has given us a firm basis on which to study the nonequilibrium behavior. 

The data presented above permit us to consider special features of IPN formation and self-organization during this process [324]. According to definition [325], self-organization involves the appearance, development, and disappearance of macroscopic structures imder nonequUibriiun conditions. Selforganization means the appearance and the development of the structure in the initially homogeneous environment. As was shown, the chemical reactions of IPN formation and phase separation in the course of reaction proceed simultaneously and under nonequilibrium conditions. 

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